From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756008AbaKSQhj (ORCPT ); Wed, 19 Nov 2014 11:37:39 -0500 Received: from service87.mimecast.com ([91.220.42.44]:39926 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755950AbaKSQhf convert rfc822-to-8bit (ORCPT ); Wed, 19 Nov 2014 11:37:35 -0500 Date: Wed, 19 Nov 2014 16:37:26 +0000 From: Liviu Dudau To: Yijing Wang Cc: Bjorn Helgaas , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "huxinwei@huawei.com" , Wuyun , "linux-arm-kernel@lists.infradead.org" , Russell King , "x86@kernel.org" , Thomas Gleixner , Benjamin Herrenschmidt , "linuxppc-dev@lists.ozlabs.org" , Tony Luck , "linux-ia64@vger.kernel.org" , Thierry Reding , Liviu Dudau , "suravee.suthikulpanit@amd.com" Subject: Re: [RFC PATCH 07/16] PCI: Separate pci_host_bridge creation out of pci_create_root_bus() Message-ID: <20141119163726.GW12037@e106497-lin.cambridge.arm.com> References: <1416219710-26088-1-git-send-email-wangyijing@huawei.com> <1416219710-26088-8-git-send-email-wangyijing@huawei.com> <20141118153020.GL12037@e106497-lin.cambridge.arm.com> <546BF59C.8060203@huawei.com> MIME-Version: 1.0 In-Reply-To: <546BF59C.8060203@huawei.com> User-Agent: Mutt/1.5.22 (2013-10-16) X-OriginalArrivalTime: 19 Nov 2014 16:37:27.0760 (UTC) FILETIME=[1B01B500:01D00417] X-MC-Unique: 114111916373203101 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 19, 2014 at 01:42:52AM +0000, Yijing Wang wrote: > On 2014/11/18 23:30, Liviu Dudau wrote: > > On Mon, Nov 17, 2014 at 10:21:41AM +0000, Yijing Wang wrote: > >> There are some common PCI infos like domain, msi_controller, these > >> infos are saved in arch PCI sysdata, and lots arch specific functions > >> like pci_domain_nr() and pcibios_msi_controller() required. > >> We could separate pci_host_bridge creation out of pci_create_root_bus(), > >> then we could put the common infos in, then we could eliminate > >> the arch specifc functions. > >> > > > > Please Cc: Yinghai Lu and Jiang Liu on future versions. > > > > More comments on the conversion of pci_create_root_bus(): > > That's my mistake, will add CC Yinghai and Jiang in next version. > > > > >> Signed-off-by: Yijing Wang > >> --- > ... > >> + > >> +static void pci_release_host_bridge_dev(struct device *dev) > >> +{ > >> + struct pci_host_bridge *bridge = to_pci_host_bridge(dev); > >> + > >> + if (bridge->release_fn) > >> + bridge->release_fn(bridge); > >> + pci_free_resource_list(&bridge->windows); > >> + kfree(bridge); > >> +} > >> + > >> +struct pci_host_bridge *pci_create_host_bridge( > >> + struct device *parent, u32 db, > >> + struct pci_ops *ops, void *sysdata, > > > > I don't thinks it is worth moving the buses' pci_ops into pci_host_bridge. It > > might be more useful to have pci_host_bridge specific ops here. > > Because we want to create pci_host_bridge before pci root bus creation, > so when we scan the root bus and child buses, we use pci_host_bridge as > the only argument, and another pci_host_info will be addes in later patch, > which one support carry the pci_host_bridge ops. But pci_create_root_bus() already has a pci_ops argument, I don't see the reason to drop that. pci_create_host_bridge() can get pci_host_bridge ops while pci_create_root_bus() gets the bus ops. For find out the MSI controller, the domain number and any other HB specific stuff, you use the HB ops. For config R/W acceses you use bus ops. > > > > >> + struct list_head *resources) > >> +{ > >> + int error; > >> + struct pci_bus *b; > >> + struct pci_host_bridge *host, *h; > ... > >> -struct pci_bus *pci_create_root_bus(struct device *parent, u32 db, > >> - struct pci_ops *ops, void *sysdata, struct list_head *resources) > >> +struct pci_bus *__pci_create_root_bus(struct pci_host_bridge *bridge) > >> { > >> int error; > >> - struct pci_host_bridge *bridge; > >> struct pci_bus *b, *b2; > >> - struct pci_host_bridge_window *window, *n; > >> + struct pci_host_bridge_window *window; > >> struct resource *res; > >> resource_size_t offset; > >> char bus_addr[64]; > >> char *fmt; > >> - u8 bus = PCI_BUSNUM(db); > >> + struct device *parent = bridge->dev.parent; > >> > >> b = pci_alloc_bus(NULL); > >> if (!b) > >> return NULL; > >> > >> - b->sysdata = sysdata; > >> - b->ops = ops; > >> - b->number = b->busn_res.start = bus; > >> + b->sysdata = bridge->sysdata; > > > > I think bridge should be the b->sysdata here. > > ? what's the meaning? Currently, bus->sysdata holds a pointer to the arch/driver host bridge structure, as passed in pci_create_root_bus(). If you agree with my idea of wrapping the host bridge driver structure around the pci_host_bridge, then we will always have a way of retrieving that information; but for backwards compatibility we could set bus->sysdata to be the bridge. Then existing macros that convert sysdata to pci_controller can be reused after being updated. Best regards, Liviu > > > > >> + b->ops = bridge->ops; > > > > See comment above why I don't think this is necessary. > > > >> + b->number = b->busn_res.start = bridge->busnum; > >> pci_bus_assign_domain_nr(b, parent); > >> - b2 = pci_find_bus(pci_domain_nr(b), bus); > >> + bridge->domain = pci_domain_nr(b); > > > > Do you really want to overwrite the bridge's domain with the one from a bus that > > could possibly be rejected a couple of lines further down? > > > > As an asside: if we are doing the split of pci_host_bridge from root bus creation > > it is worth in my opinion to move the domain setup in pci_create_host_bridge() > > and stop fiddling with it here. > > > Hi Liviu, these lines just temporary, I will remove it after all host drivers > save its domain in pci_host_bridge. > > > > > > Otherwise it looks to me like you are heading in the right direction. > > Thanks! > Yijing. > > > > > Best regards, > > Liviu > > > >> + b2 = pci_find_bus(pci_domain_nr(b), bridge->busnum); > >> if (b2) { > >> /* If we already got to this bus through a different bridge, ignore it */ > >> dev_dbg(&b2->dev, "bus already known\n"); > >> goto err_out; > >> } > >> > >> - bridge = pci_alloc_host_bridge(b); > >> - if (!bridge) > >> - goto err_out; > >> - > >> - bridge->dev.parent = parent; > >> - bridge->dev.release = pci_release_host_bridge_dev; > >> - dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus); > >> - error = pcibios_root_bridge_prepare(bridge); > >> - if (error) { > >> - kfree(bridge); > >> - goto err_out; > >> - } > >> - > >> - error = device_register(&bridge->dev); > >> - if (error) { > >> - put_device(&bridge->dev); > >> - goto err_out; > >> - } > >> b->bridge = get_device(&bridge->dev); > >> device_enable_async_suspend(b->bridge); > >> pci_set_bus_of_node(b); > >> @@ -1950,7 +1899,7 @@ struct pci_bus *pci_create_root_bus(struct device *parent, u32 db, > >> > >> b->dev.class = &pcibus_class; > >> b->dev.parent = b->bridge; > >> - dev_set_name(&b->dev, "%04x:%02x", pci_domain_nr(b), bus); > >> + dev_set_name(&b->dev, "%04x:%02x", pci_domain_nr(b), b->number); > >> error = device_register(&b->dev); > >> if (error) > >> goto class_dev_reg_err; > >> @@ -1966,12 +1915,11 @@ struct pci_bus *pci_create_root_bus(struct device *parent, u32 db, > >> printk(KERN_INFO "PCI host bridge to bus %s\n", dev_name(&b->dev)); > >> > >> /* Add initial resources to the bus */ > >> - list_for_each_entry_safe(window, n, resources, list) { > >> - list_move_tail(&window->list, &bridge->windows); > >> + list_for_each_entry(window, &bridge->windows, list) { > >> res = window->res; > >> offset = window->offset; > >> if (res->flags & IORESOURCE_BUS) > >> - pci_bus_insert_busn_res(b, bus, res->end); > >> + pci_bus_insert_busn_res(b, b->number, res->end); > >> else > >> pci_bus_add_resource(b, res, 0); > >> if (offset) { > >> @@ -2001,6 +1949,25 @@ err_out: > >> return NULL; > >> } > >> > >> +struct pci_bus *pci_create_root_bus(struct device *parent, u32 bus, > >> + struct pci_ops *ops, void *sysdata, struct list_head *resources) > >> +{ > >> + struct pci_host_bridge *host; > >> + > >> + host = pci_create_host_bridge(parent, bus, ops, > >> + sysdata ,resources); > >> + if (!host) > >> + return NULL; > >> + > >> + host->bus = __pci_create_root_bus(host); > >> + if (!host->bus) { > >> + pci_free_host_bridge(host); > >> + return NULL; > >> + } > >> + > >> + return host->bus; > >> +} > >> + > >> int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max) > >> { > >> struct resource *res = &b->busn_res; > >> @@ -2069,40 +2036,37 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db, > >> { > >> struct pci_host_bridge_window *window; > >> bool found = false; > >> - struct pci_bus *b; > >> - LIST_HEAD(default_res); > >> + struct pci_host_bridge *host; > >> int max; > >> > >> - if (!resources) { > >> - pci_add_resource(&default_res, &ioport_resource); > >> - pci_add_resource(&default_res, &iomem_resource); > >> - pci_add_resource(&default_res, &busn_resource); > >> - } else { > >> - list_for_each_entry(window, resources, list) > >> - if (window->res->flags & IORESOURCE_BUS) { > >> - found = true; > >> - break; > >> - } > >> - } > >> + host = pci_create_host_bridge(parent, db, ops, sysdata, resources); > >> + if (!host) > >> + return NULL; > >> > >> - b = pci_create_root_bus(parent, db, ops, sysdata, > >> - resources ? resources : &default_res); > >> - if (!b) > >> + list_for_each_entry(window, &host->windows, list) > >> + if (window->res->flags & IORESOURCE_BUS) { > >> + found = true; > >> + break; > >> + } > >> + > >> + host->bus = __pci_create_root_bus(host); > >> + if (!host->bus) { > >> + pci_free_host_bridge(host); > >> return NULL; > >> + } > >> > >> if (!found) { > >> - dev_info(&b->dev, > >> + dev_info(&host->bus->dev, > >> "No busn resource found for root bus, will use [bus %02x-ff]\n", > >> PCI_BUSNUM(db)); > >> - pci_bus_insert_busn_res(b, PCI_BUSNUM(db), 255); > >> + pci_bus_insert_busn_res(host->bus, PCI_BUSNUM(db), 255); > >> } > >> > >> - max = pci_scan_child_bus(b); > >> - > >> + max = pci_scan_child_bus(host->bus); > >> if (!found) > >> - pci_bus_update_busn_res_end(b, max); > >> + pci_bus_update_busn_res_end(host->bus, max); > >> > >> - return b; > >> + return host->bus; > >> } > >> EXPORT_SYMBOL(pci_scan_root_bus); > >> > >> diff --git a/include/linux/pci.h b/include/linux/pci.h > >> index 8b11b38..daa7f40 100644 > >> --- a/include/linux/pci.h > >> +++ b/include/linux/pci.h > >> @@ -402,7 +402,12 @@ struct pci_host_bridge_window { > >> struct pci_host_bridge { > >> struct device dev; > >> struct pci_bus *bus; /* root bus */ > >> + struct list_head list; > >> struct list_head windows; /* pci_host_bridge_windows */ > >> + int busnum; > >> + int domain; > >> + void *sysdata; > >> + struct pci_ops *ops; > >> void (*release_fn)(struct pci_host_bridge *); > >> void *release_data; > >> }; > >> @@ -413,7 +418,9 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge, > >> void *release_data); > >> > >> int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge); > >> - > >> +struct pci_host_bridge *pci_create_host_bridge( > >> + struct device *parent, u32 db, struct pci_ops *ops, > >> + void *sys, struct list_head *resources); > >> /* > >> * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond > >> * to P2P or CardBus bridge windows) go in a table. Additional ones (for > >> @@ -770,6 +777,8 @@ void pci_bus_add_devices(const struct pci_bus *bus); > >> struct pci_bus *pci_create_root_bus(struct device *parent, u32 bus, > >> struct pci_ops *ops, void *sysdata, > >> struct list_head *resources); > >> +struct pci_bus *__pci_create_root_bus(struct pci_host_bridge *host); > >> +void pci_free_host_bridge(struct pci_host_bridge *host); > >> int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax); > >> int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax); > >> void pci_bus_release_busn_res(struct pci_bus *b); > >> -- > >> 1.7.1 > >> > >> -- > >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in > >> the body of a message to majordomo@vger.kernel.org > >> More majordomo info at http://vger.kernel.org/majordomo-info.html > >> > > > > > -- > Thanks! > Yijing > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯